Recently, equipment with a touch panel has become widespread. Some touch panels are equipped with a tactile-sensation transmitting device that gives a user a tactile sensation when the user has touched a touch panel by using the squeeze effect of an actuator such as a piezoelectric element which vibrates with applied voltage. The squeeze effect is to generate standing-wave vibration with a ultrasonic frequency of, for example, about 30 KHz on a touch panel, thereby a tactile sensation is given to the user's finger that has touched the touch panel.                [Patent Literature 1] Japanese Laid-open Patent Publication No. 2012-014341        [Patent Literature 2] Japanese Laid-open Patent Publication No. 2011-048698        
However, since standing-wave vibration has nodes and antinodes, user's tactile sensation may differ according to which is closer to the touch position of the user's finger in touch with a touch panel, a node or an antinode of the standing-wave vibration. That is, the above-described conventional technology has a problem that user's tactile sensation varies according to the touch position on the touch panel.
As a suggestion, a terminal device detects the position of a user's touch operation performed on a touch panel. Then, the terminal device determines whether the position of the touch operation is within a predetermined distance from the position of some antinode of standing-wave vibration generated on the touch panel by a first actuator attached to the touch panel so as to transmit a tactile sensation from the touch position on the touch panel. If the terminal device has determined that the position of the touch operation is not within the predetermined distance from some antinode of the standing-wave vibration, the terminal device performs the following process. That is, the terminal device changes the position of antinodes of the standing-wave vibration by controlling a second actuator that is attached to the inner side of the touch panel than the first actuator and pressurizes the touch panel.